The present invention concerns an electronic device, particularly an electronic device having a surface mount package, and it relates to a useful technique applicable, for example, to a semiconductor integrated circuit device (hereinafter simply referred to as IC) having Gull-Wing outer leads.
As ICs having surface mount packages, those having Gull-Wing outer leads have been known, in which solder plating treatment has been applied to the surface of the Gull-Wing outer leads for improving the solderability upon surface mounting. The plating treatment is applied after forming the package to a lead frame. After applying the plating, the connection portion between the outer leads and the outer frame in the lead frame are cut and the Gull-Wing shape of the outer leads is formed by bending.
The surface mount package is described, for example, in "Micro Devices No. 2", pages 148-154, published by Nikkei McGraw-Hill, on June 11, 1984.
Further, Japanese Patent Laid-Open No. Sho 61-75553 discloses an idea of improving the solder wettability upon mounting in a surface mount plastic package by reducing the width of the lead tips.